Acute kidney injury represents a major complication of vancomycin treatment, especially when it is co-administered with other nephrotoxins. This meta-analysis aims to comparatively assess the nephrotoxicity of antipseudomonal beta-lactams when combined with vancomycin.Medline, Scopus, CENTRAL and Clinicaltrials.gov databases were systematically searched from inception through 20 August 2019.Studies evaluating acute kidney injury risk following the concurrent use of antipseudomonal beta-lactams and vancomycin were selected.Adult and pediatric patients treated in hospital or intensive care unit.Administration of vancomycin combined with any antipseudomonal beta-lactam.Acute kidney injury incidence was defined as the primary outcome. Secondary outcomes included severity, onset, duration, need of renal replacement therapy, length of hospitalization and mortality. Quality of evidence was assessed using the ROBINS-I tool and the Confidence In Network Meta-Analysis approach.Forty-seven cohort studies were included, with a total of 56,984 patients. In the adult population, the combination of piperacillin-tazobactam and vancomycin resulted in significantly higher nephrotoxicity rates compared to vancomycin monotherapy (Odds ratio-OR: 2.05, 95% confidence intervals-CI [1.17-3.46]) and its concurrent use with meropenem (OR: 1.84, 95% CI [1.02-3.10]) or cefepime (OR: 1.80, 95% CI [1.13-2.77]). In pediatric patients, acute kidney injury was significantly higher with vancomycin plus piperacillin-tazobactam than vancomycin alone (OR: 4.18, 95% CI [1.01-17.29]) or vancomycin plus cefepime OR: 3.71, 95% CI [1.08-11.24]). No significant differences were estimated for the secondary outcomes. Credibility of outcomes was judged as moderate, mainly due to imprecision and inter-study heterogeneity.The combination of vancomycin and piperacillin-tazobactam is associated with higher acute kidney injury rates compared to its parallel use with meropenem or cefepime. Current evidence is exclusively observational and is limited by inter-study heterogeneity. Randomized controlled trials are needed to verify these results and define preventive strategies to minimize nephrotoxicity risk.